Never cleaned it before, and just today, when I took off one of my lens, I saw some dust on the mirror. Question is, how should I clean the mirror and the other internals? Seems like my blower/brush thingy would be too harsh for it. Any advice would be greatly appreciated! Thanks!

It can be but you have to be very careful. There are special kits with cleaning tools and highly refined cleaning alchohol. You can find them pretty easily. Just make sure you look into what it requires and then decide if its something you want to do

I'm with Matt, don't worry too much about the mirror as it's very delicate. The sensor actually has a protective sheet or coating and is not as delicate as most people seem to think. Check out the links above.

Ah, thanks for the replies fellas. I didn't know the mirror was more delicate than the sensor itself. If that's the case, I can put off cleaning it a bit. I took my air bulb cleaning tool and most of the dust off the mirror. Everything in there seems clean for the time being, but I will definately read up on those links you all provided. Thanks again!